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With the immense progress in wireless communication, antenna designing is an interesting research area. Antenna is a device that converts electrical energy into electromagnetic waves, making wireless communication possible. Presently, the use of mobile phones is increasing with a high rate, especially with the arrival of smart phones in market. The 3G and 4G technology has added further to the time one remain busy on his cell phone. This has led to human exposure to the harmful radiations from cell phone antenna for prolonged time. The radiations have a heating effect on the human body especially on head region. To reduce the harmful effect of radiations from antenna is the cry of the day. This has been an interesting area for researchers from all over the world to design an antenna with no harmful effect on human health. When we talk on our cell phone, our voice is transmitted from the antenna of the cell phone as radio frequency radiation (RFR) between 800 MHz and 1,990 MHz. This frequency falls in the range of microwave radiation and we are exposed to it. Cell phones are designed to transmit radio waves in all directions because base stations can be located in any direction with respect to phone users. This means that portions of the radio waves they produce are directed towards our body. Thesis can be download from here; http://topgravity.com/fyp-specific-absorption-rate-reduction-using-ebg-structures/
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Project Supervisor: : Dr. Shahid Bashir
Department of Electrical Engineering , University of Engineering & Technology, Peshawar
Syed Muhammad Bilal (10PWELE3806)Riaz ul Amin (10PWELE3799)Imran Ullah Khan (10PWELE3800)Abdirisak Mohamud (10PWELE3884)
Top Gravity : http://topgravity.com/Facebook :https://www.facebook.com/MindStudentsTwitter :https://twitter.com/mytopgravity
IntroductionProblem StatementProposed SolutionResearch MethodologyProposed DesignResultsConclusion
Progress in 3G and 4G technologyDevelopment in Smart phonesProlong exposure to harmful radiationsCauses heating effect in human tissue especially brain
Reducing the harmful effect is the need of present dayGlobally , a parameter known as Specific Absorption Rate (SAR)SAR is defined as the power absorbed per mass of tissue and has unit of watts/kgAim of our project is to reduce the SAR value
Radiations from portabledevices produce heatin human body
Strong need to reduce thisharmful effect
Using EBGs reduces the harmful effect by blocking the flow of surface wavesEBGs acts as LC circuit
A square patch antenna for 3.5GHZ band (WIMAX applications) has been designed.
Maximum dimensions of antenna are 45mm ×45mmDesign and simulation in CST
Proposed EBG has unit cell size of 10mm×10mmWith vias at the center
modified from conventional mushroom EBG to reduce unit cell sizeCross slots are used
Conventional EBG unit cell size for this band is 12mm×12mmSize reduction of 2mm has been obtained
A total of 12 unit cells are placed around the patchFor best coupling the distance between patch and EBG cells is 1mm
Antenna without EBG
Return loss plot is shownA gain of 4.54dbi
SAR calculation of antenna without EBGThe Cylinder with properties of human skin is placed at distance of 10mm (1 cm)Peak SAR value is 0.135 watts/kg
SAR calculation of antenna with EBGSame 10mm distance Peak SAR value is 0.058W/kgReduction of 57%
Remarkable SAR reduction by 57%EBG unit cell size reduction by 2mmImprovement in matching of antenna
EBGs are very effective in SAR reductionEBG unit cell size is large for low frequency applications EBG degrade certain antenna parameters
Proposed EBG has degraded the antenna gain and centralized frequencyFurther improvement can be made in this regard
Readers can download our thesis from here.http://topgravity.com/fyp-specific-absorption-rate-reduction-using-ebg-structures/